Self-locking features in a multi-chip module

Abstract

A multi-chip module (MCM) is described. This MCM includes at least two substrates that are remateably mechanically coupled by positive and negative features on facing surfaces of the substrates. These positive and negative features may mate and self-lock with each other. For example, the positive features on one of the surfaces may include pairs of counterposed micro-springs, and the negative features may include pits or grooves on the other surface. When the substrates are mechanically coupled, a given pair of positive features may provide a force in a plane of the other surface. Furthermore, by compressing the MCM so that the surfaces of the substrates are pushed toward each other, the mechanical coupling may be released.

1. A multi-chip module (MCM), comprising:
 a first substrate having a first surface, wherein the first substrate includes first negative features disposed on the first surface, and wherein a given first negative feature is recessed below the first surface and has an opening, defined by an edge; and 
 a second substrate having a second surface that faces the first surface, wherein the second substrate includes first positive features disposed on the second surface; 
 wherein a given first positive feature protrudes above the second surface; and 
 wherein the first positive features are configured to mate and self-lock with the first negative features, thereby mechanically coupling the first substrate and the second substrate, 
 wherein the mechanical coupling of the first substrate and the second substrate is remateable and is released by compressing the MCM so that the first surface and the second surface are pushed toward each other. 
 
     
     
       2. The MCM of  claim 1 , wherein the first positive features include micro-spring connectors. 
     
     
       3. The MCM of  claim 1 , wherein the first positive features include counterposed pairs of first positive features that mechanically couple to associated pairs of first negative features; and
 wherein mechanical coupling by a given counterposed pair of first positive features involves a force provided by the given counterposed pair of first positive features in a plane of the first surface. 
 
     
     
       4. The MCM of  claim 1 , wherein the first negative features include pits. 
     
     
       5. The MCM of  claim 1 , wherein the first positive features and the first negative features electrically couple the first substrate and the second substrate. 
     
     
       6. The MCM of  claim 1 , wherein the first substrate includes electrical connectors disposed on the first surface;
 wherein the second substrate includes second positive features disposed on the second surface; 
 wherein a given second positive feature protrudes above the second surface; and 
 wherein the second positive features are configured to contact the electrical connectors, thereby electrically coupling the first substrate and the second substrate. 
 
     
     
       7. The MCM of  claim 1 , wherein the second substrate includes electrical connectors disposed on the second surface;
 wherein the first substrate includes second positive features disposed on the first surface; 
 wherein a given second positive feature protrudes above the first surface; and 
 wherein the second positive features are configured to contact the electrical connectors, thereby electrically coupling the first substrate and the second substrate. 
 
     
     
       8. The MCM of  claim 1 , wherein the first negative features are arranged in groups, which include two or more first negative features;
 wherein the first positive features are associated with the groups; and 
 wherein the mechanical coupling involves mating and self-locking of the given first positive feature with one of the two or more first negative features in a given group, thereby accommodating process variation and misalignment in the MCM. 
 
     
     
       9. The MCM of  claim 1 , wherein symmetry directions of the first positive features are arranged along a first direction in the plane of the second surface. 
     
     
       10. The MCM of  claim 1 , wherein symmetry directions of the first positive features are arranged along a first direction and a second direction in the plane of the second surface; and
 wherein the first direction and the second direction are approximately perpendicular. 
 
     
     
       11. The MCM of  claim 1 , wherein symmetry directions of the first positive features are arranged in radial directions in the plane of the second surface; and
 wherein the radial directions radiate out from a common point or region on the second surface. 
 
     
     
       12. The MCM of  claim 1 , wherein the given first negative feature includes an undercut of the first surface. 
     
     
       13. The MCM of  claim 1 , wherein the first substrate includes second positive features disposed on the first surface, wherein a given second positive feature protrudes above the first surface;
 wherein the second substrate includes second negative features disposed on the second surface, wherein a given second negative feature is recessed below the second surface and has an opening, defined by an edge; and 
 wherein the second positive features are associated with the second negative features, and are configured to mate and self-lock with the second negative features, thereby mechanically coupling the first substrate and the second substrate. 
 
     
     
       14. An electronic device, comprising an MCM, wherein the MCM includes:
 a first substrate having a first surface, wherein the first substrate includes first negative features disposed on the first surface, and wherein a given first negative feature is recessed below the first surface and has an opening, defined by an edge; and 
 a second substrate having a second surface that faces the first surface, wherein the second substrate includes first positive features disposed on the second surface; 
 wherein a given first positive feature protrudes above the second surface; and 
 wherein the first positive features are configured to mate and self-lock with the first negative features, thereby mechanically coupling the first substrate and the second substrate, 
 wherein the mechanical coupling of the first substrate and the second substrate is remateable and is released by compressing the MCM so that the first surface and the second surface are pushed toward each other. 
 
     
     
       15. A multi-chip module (MCM), comprising:
 a first substrate having a first surface, wherein the first substrate includes first negative features disposed on the first surface, and wherein a given first negative feature is recessed below the first surface and has an opening, defined by an edge; and 
 a second substrate having a second surface that faces the first surface, wherein the second substrate includes first positive features disposed on the second surface; 
 wherein a given first positive feature protrudes above the second surface; and 
 wherein the first positive features are configured to mate and self-lock with the first negative features, thereby mechanically coupling the first substrate and the second, 
 wherein the first negative features include a mechanically compliant material that facilitates the mechanical coupling, and wherein, when the first positive features mate with the first negative features, tips of the first positive features become at least partially embedded in the mechanically compliant material. 
 
     
     
       16. The MCM of  claim 15 , wherein the mechanically compliant material includes a polymer. 
     
     
       17. The MCM of  claim 15 , wherein the mechanically compliant material facilitates rigid mechanical coupling of the first substrate and the second substrate.